Climate affects children who have atopic dermatitis, a recurrent disease of the skin. This is suggested in a study headed by Spanish researchers that links this disease with rainy and humid areas. However, the experts point out that both temperature and the number of hours of sunshine combine in the treatment of this condition.

María Morales Suárez-Varela, who is the principal author of the study and a researcher at the University of Valencia, explains this to SINC. “The study documents the possible influence of climate on the prevalence of atopic dermatitis in girls and boys aged 6 and 7, in the three climatic regions of Spain-- the Atlantic, Mediterranean and Continental regions,” she says.

To show this, the study, which is published in the International Journal of Biometeorology, analyzes 28,394 cases of children from the Spanish cities of Asturias, Bilbao, La Coruna, Pamplona, San Sebastián, Barcelona, Cartagena, Castellón, Valencia and Madrid. All these places are situated in the three climatic regions of Spain. The study uses the questionnaire from the International Study of Asthma and Allergies in Childhood (ISAAC) in order to determine the prevalence of atopic dermatitis in the population, using criteria from the Spanish Academy of Dermatology and Venereology (Academia Espanola de Dermatología y Venereología.

Moreover, the researchers have analyzed data provided by the Spanish Meteorological Agency (Agencia Estatal de Metereología) concerning annual temperature, rainfall, relative humidity and the number of hours of sunshine for each of the regions. “Significant differences in the prevalence of the disease were detected in the three regions studied (32.9% in the Atlantic area, 28.3% in the Mediterranean area and 31.2% in the Continental area)”, outlines the researcher from Valencia. The results showed that atopic dermatitis depends on meteorological conditions.

"Given that our data suggests that the disease appears to be associated positively with rainfall and humidity, and associated negatively with temperature and the number of hours of sunshine, the appearance of dermatitis could be prevented, and the status of the lesions could be improved,” Suárez-Varela emphasises to SINC.

Who has dermatitis?

Dermatitis, or atopic eczema, is a chronic disease of the skin that affects a very high proportion of the population. According to the data from the Spanish Pediatric Association (Asociación Espanola de Pediatría), one out of every 20 children has dermatitis, and its incidence has increased, “probably due to a high concentration of irritants in the atmosphere,” according to the study.

Atopic dermatitis turns areas of the skin red on which tiny blisters form (eczema). It usually appears during the first years of life, although not before three months of age, and then reduces in intensity and duration slowly as it grows. The disease can also appear in adults, and varies in location, depending on age. Both environmental factors as well as genetic predisposition are involved in this disease.

“The problem is that the set of criteria for diagnosing dermatitis is complex as there are various schools of thought, and usually it is accompanied by nappy rash or other types of lesions. The difference is that atopic dermatitis suggests that the origin of the disease is entirely unknown,” concludes the author.